Sequestosome 1 (SQSTM1/p62) is a selective autophagy adaptor protein that plays an important role in the clearance of proteins to be degraded as well as in the maintenance of cellular proteostasis. p62 protein has multiple functional domains, which interact with several downstream proteins to precisely regulate multiple signaling pathways, thereby linking p62 to oxidative defense systems, inflammatory responses and nutrient sensing. Studies have shown that mutation or abnormal expression of p62 is closely related to the occurrence and development of various diseases, including neurodegenerative diseases, tumors, infectious diseases, genetic diseases and chronic diseases. This review summarizes the structural features and molecular functions of p62. Moreover, we systematically introduce its multiple functions in protein homeostasis and regulation of signaling pathways. Furthermore, the complexity and versatility of p62 in the occurrence and development of diseases are summarized, with the aim to provide a reference for understanding the function of p62 protein and facilitating related disease research.
Humans ; Autophagy/genetics* ; Sequestosome-1 Protein/metabolism* ; Adaptor Proteins, Signal Transducing/metabolism* ; Signal Transduction ; Neoplasms/genetics*

BACKGROUND: Arteriosclerosis obliterans (ASO) is a major cause of adult limb loss worldwide. Autophagy of vascular endothelial cell (VEC) contributes to the ASO progression. However, the molecular mechanism that controls VEC autophagy remains unclear. In this study, we aimed to explore the role of the GRB2 associated binding protein 1 (GAB1) in regulating VEC autophagy. METHODS: In vivo and in vitro studies were applied to determine the loss of adapt protein GAB1 in association with ASO progression. Histological GAB1 expression was measured in sclerotic vascular intima and normal vascular intima. Gain- and loss-of-function of GAB1 were applied in VEC to determine the effect and potential downstream signaling of GAB1. RESULTS: The autophagy repressor p62 was significantly downregulated in ASO intima as compared to that in healthy donor (0.80 vs. 0.20, t = 6.43, P < 0.05). The expression level of GAB1 mRNA (1.00 vs. 0.24, t = 7.41, P < 0.05) and protein (0.72 vs. 0.21, t = 5.97, P < 0.05) was significantly decreased in ASO group as compared with the control group. Loss of GAB1 led to a remarkable decrease in LC3II (1.19 vs. 0.68, t = 5.99, P < 0.05), whereas overexpression of GAB1 significantly led to a decrease in LC3II level (0.41 vs. 0.93, t = 7.12, P < 0.05). Phosphorylation levels of JNK and p38 were significantly associated with gain- and loss-of-function of GAB1 protein. CONCLUSION Loss of GAB1 promotes VEC autophagy which is associated with ASO. GAB1 and its downstream signaling might be potential therapeutic targets for ASO treatment.
Adaptor Proteins, Signal Transducing ; Adult ; Arteriosclerosis Obliterans/genetics* ; Autophagy ; GRB2 Adaptor Protein ; Humans ; Phosphoproteins/metabolism* ; Phosphorylation ; Protein Binding ; Signal Transduction

PURPOSE: Recently, COMMD1 has been identified as a novel interactor and regulator of hypoxia-inducible factor-1 and nuclear factor kappa B transcriptional activity. The goal of this study was to determine the difference of COMMD1 expression in the placentas of women with normal and preeclamptic (PE) pregnancies. MATERIALS AND METHODS: Immnoperoxidase and immunofluorescent staining for COMMD1 was performed on nine normal and nine severe PE placental tissues, and COMMD1 mRNA expression was quantified by quantitative reverse transcription polymerase chain reaction. RESULTS: The expression of mRNA of COMMD1 was significantly higher in the study group than in the control group. The immunoreactivity was higher especially in the syncytiotrophoblast of PE placentas than in the control group. CONCLUSION: This study demonstrated increased placental COMMD1 expression in women with severe preeclampsia compared to that found in women with normal pregnancies, and this finding might contribute to a better understanding of the pathophysiology of preeclampsia.
Adaptor Proteins, Signal Transducing/genetics/isolation & purification/*metabolism ; Adult ; Female ; Humans ; Placenta/*metabolism ; Pre-Eclampsia/*metabolism ; Pregnancy ; RNA, Messenger/metabolism

OBJECTIVE: To investigate the effect of silencing DNA methyltransferase 1(DNMT1) to the methylation of the promoter of the tumor suppressor gene wnt-1 (WIF-1) in human chronic myeloid leukemia (CML) cells. METHODS: DNMT1 siRNAi plasmid was constructed and DNMT1 siRNAi was transfected into CML K562 cells. RT-PCR and Western blot were used to detect the expression of DNMT1 gene and related protein, and methylation PCR was used to detect WIF-1 gene promoter methylation level. The trypan blue exclusion and MTT assay were used to detect the cell proliferation, flow cytometry were used to detect the cell apoptosis rate, colony formation assay was used to detect cell colony formation ability. Expression of Wnt/β- catenin and its downstream signaling pathway proteins were detected by Western blot after DNMT1 gene was silenced. RESULTS: The expression level of DNMT1 mRNA and its related protein in the experimental group were significantly lower than those in the control group and negative control group (P<0.05). After 72 hours of successful transfection, the WIF-1 gene in the control group and negative control group were completely methylated, while in the experimental group, the methylation level significantly decreased. The results of MSP showed that the PCR product amplified by the unmethylated WIF-1 primer in the experimental group increased significantly,while by the methylated WIF-1 primer decreased significantly. After 48 h of transfection, the OD value, viable cell number and colony formation of the cells in experimental group were significantly lower than those in the negative control group and the control group (P<0.05). The apoptosis rate of the cells in experimental group was significantly higher than those in the negative control group and control group (P<0.05). The expression levels of β- actin, myc, cyclin D1 and TCF-1 in K562 cells in the experimental group were significantly lower than those in the negative control group and control group (P<0.05). CONCLUSION Silencing DNMT1 gene can inhibit the proliferation and promote the apoptosis of K562 cells. The mechanism may be related to reverse the hypermethylation level of the WIF-1 gene promoter, thereby inhibit the activity of the Wnt/β- catenin signaling pathway.
Adaptor Proteins, Signal Transducing/metabolism* ; DNA Methylation ; Humans ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics* ; Repressor Proteins/metabolism*

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Animals ; Energy Metabolism ; genetics ; Growth Hormone ; metabolism ; Humans ; Insulin ; metabolism ; Longevity ; genetics ; Metabolism ; genetics ; Signal Transduction ; genetics

OBJECTIVESPAG9, as a member of the MAPK family, plays an important role in sperm-egg fusion. This study aimed to detect the expression of SPAG9 in human ejaculated spermatozoa.

METHODSDifferent human tissues (as from the muscle, liver, esophagus, lung, stomach, kidney, prostate, uterus, testis and epididymis) and semen samples were obtained from healthy volunteers, and semen analyses were performed according to the WHO criteria. Human ejaculated spermatozoa were purified by discontinuous Percoll density gradient centrifugation to rule out the contamination of germ cells and leucocytes. RT-PCR and indirect immunofluorescence were used to detect the expression of SPAG9 in human spermatozoa.

RESULTSRT-PCR showed that SPAG9 mRNA was expressed in different tissues and human ejaculated spermatozoa. Indirect immunofluorescence studies revealed the location of SPAG9 protein in the equatorial plate and flagella of human spermatozoa.

CONCLUSIONSPAG9 is expressed in ejaculated spermatozoa and may play a role in sperm capacitation and motility.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Fluorescent Antibody Technique, Indirect ; Humans ; Male ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatozoa ; metabolism

As an important part of tumor microenvironment, neutrophils are poorly understood due to their spatiotemporal heterogeneity in tumorigenesis. Here we defined, at single-cell resolution, CD44-CXCR2- neutrophils as tumor-specific neutrophils (tsNeus) in both mouse and human gastric cancer (GC). We uncovered a Hippo regulon in neutrophils with unique YAP signature genes (e.g., ICAM1, CD14, EGR1) distinct from those identified in epithelial and/or cancer cells. Importantly, knockout of YAP/TAZ in neutrophils impaired their differentiation into CD54+ tsNeus and reduced their antitumor activity, leading to accelerated GC progression. Moreover, the relative amounts of CD54+ tsNeus were found to be negatively associated with GC progression and positively associated with patient survival. Interestingly, GC patients receiving neoadjuvant chemotherapy had increased numbers of CD54+ tsNeus. Furthermore, pharmacologically enhancing YAP activity selectively activated neutrophils to suppress refractory GC, with no significant inflammation-related side effects. Thus, our work characterized tumor-specific neutrophils in GC and revealed an essential role of YAP/TAZ-CD54 axis in tsNeus, opening a new possibility to develop neutrophil-based antitumor therapeutics.
Humans ; Animals ; Mice ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Stomach Neoplasms/pathology* ; Neutrophils/pathology* ; Signal Transduction/genetics* ; YAP-Signaling Proteins ; Tumor Microenvironment ; Hyaluronan Receptors/genetics*

BACKGROUNDOral squamous cell carcinoma (OSCC) is one of the most common malignancies in the oral and maxillofacial region. Yes-associated protein 1 (YAP1) has been implicated as a bona fide oncogene in solid tumors. We seek to elucidate the role of YAP1 in OSCC tissue.

METHODSWe identified YAP1 gene and protein overexpression in 30 OSCC patients and 10 normal oral mucosa tissues by immunohistochemistry, Western blotting and reverse transcription polymerase chain reaction (RT-PCR).

RESULTSIn the normal oral mucosa by immunohistochemical staining, YAP1 mainly located in both the cytoplasm and nucleus mainly the nuclei of the basal cells. In OSCC, the expression of YAP1 translocated from the nucleus to cytoplasm; YAP1 being mainly located in both the cytoplasm and nucleus of the adjacent mucosa. The expression of YAP1 gradual increased in normal oral mucosa, tumor adjacent mucosa and low grade, middle grade, high grade OSCC tissue by Western blotting. Significant difference was found between the expressions of the normal oral mucosa and OSCC tissue (P < 0.05). The coincidence was detected between the normal oral mucosa and OSCC tissue by RT-PCR (P < 0.05).

CONCLUSIONSYAP1 is involved in the carcinogenesis and development of OSCC. There is a transformation between nucleus and cytoplasm.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Blotting, Western ; Carcinoma, Squamous Cell ; genetics ; metabolism ; Humans ; In Vitro Techniques ; Mouth Neoplasms ; genetics ; metabolism ; Phosphoproteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

PRAS40, a proline-rich Akt substrate of 40 kD, is 14-3-3 binding protein. To study the interaction between PRAS40 and 14-3-3 isoforms, We constructed the expression vector pEG-PRAS40 (DNA-binding plasmid) and pJG-PRAS40 (transcriptional activity plasmid) in yeast using gateway cloning technology, then the plasmid of pEG-PRAS40/pJG-PRAS40 was co-transformed into yeast EGY48 strain with each pJG-14-3-3 /pEG-14-3-3 isoform plasmid. The co-transformation were tested by nutrition limitation growth analysis, beta-galactosidase color assay was used to study the interaction degree between PRAS40 and 14-3-3 isoforms. We confirmed successfully the construction of pJG-PRAS40 and pEG-PRAS40 with enzyme digestion. four 14-3-3 isoforms were found interacting with PRAS40 using yeast two-hybrid assay, the interaction degree of Epsilon was stronger than beta and zeta, tau was the weakest. Our result will be used to further study the biological function of PRAS40 and 14-3-3 as new drug target.
14-3-3 Proteins ; genetics ; metabolism ; Adaptor Proteins, Signal Transducing ; Humans ; Phosphoproteins ; genetics ; metabolism ; Protein Binding ; Protein Isoforms ; genetics ; metabolism ; Two-Hybrid System Techniques

Adaptor Proteins, Signal Transducing ; chemistry ; genetics ; metabolism ; Animals ; Humans ; Nuclear Proteins ; chemistry ; genetics ; metabolism ; Protein Domains ; Protein Structure, Quaternary ; X-linked Nuclear Protein ; chemistry ; genetics ; metabolism